Visibility (uv) data is delivered for both the spectral lines and continuum.

The format for each spectral line uv data file in a MASSES dataverse is:
targetname].[configuration].[linename].[tracknumber].uvfits

The format for the continuum uv data in a MASSES dataverse is: 
[targetname].[configuration].cont[wavelength].[sideband].[tracknumber].uvfits

In the first MASSES data release (Stephens et al. 2018), the SMA configuration is in the subcompact (sub) array. The delivered spectral lines are 12CO21, 13CO21, C18O21, and N2DP. High velocity CO (highvelCO) is delivered for ASIC data. The continuum is at 1.3 mm, and is delivered separately for the lower and upper sidebands (lsb and usb, respectively). 

For Per-emb-39, there are three tracks, which were combined when imaging.
Track 160917 was taken with the SWARM correlator.
Track 160927 was taken with the SWARM correlator.
Track 170122 was taken with the SWARM correlator.

To import uvfits files into miriad, the "fits" task should be used. "op=uvin" and "options=varwt" must be specified. We show an example for CO(2-1) below:
fits in=Per39.sub.12CO21.160917.uvfits out=Per39.sub.12CO21.160917.miriad.uv op=uvin options=varwt

To import into casa, the task importuvfits should be used:
importuvfits(fitsfile="Per39.sub.12CO21.160917.uvfits",vis="Per39.sub.12CO21.160917.casa.uv")
Rest frequencies for each spectral line need to be specified in casa to show proper velocities.

This dataset also includes the full SWARM visibility data. If the user is only interested in continuum or the spectral lines 12CO21, 13CO21, C18O21, or N2DP, these datafiles do NOT need to be used. The user should only use the data specified above.
SWARM visibility data has NOT had the continuum subtracted, like the data discussed above.
The format for the SWARM data is:
[targetname].[configuration].SWARM.[sideband].s[chunknumber].[tracknumber]

These data can be imported in miriad or casa in the same way as above.
For these SWARM full visibility data, continuum subtraction should be done near the spectral line of interest. Continuum subtraction can be done with miriad task 'uvlin' or with the casa task 'uvcontsub'.
